GPT-5.5 API

GPT-5.5 is a large language model by OpenAI, available on the Venice API as openai-gpt-55. Requests are anonymized, so the provider never sees your identity.GPT-5.5 is the latest frontier model in the GPT-5 series with a 1M+ context window, offering improved agentic and long context performance. It uses adaptive reasoning to dynamically allocate computation across tasks.

GPT-5.5 API pricing

Model ID	Variant	Privacy	Price
`openai-gpt-55`	Standard	Anonymized	$6.25 input /$ 37.50 output per 1M tokens

GPT-5.5 specifications

Spec	Value
Provider	OpenAI
Released	Apr 23, 2026
Privacy	Anonymized
Context window	1M tokens
Max output	128K tokens
Reasoning effort	none, low, medium, high, xhigh

How to use the GPT-5.5 API

Send requests to POST https://api.venice.ai/api/v1/responses with "model": "openai-gpt-55" and your API key.

curl https://api.venice.ai/api/v1/responses \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai-gpt-55",
    "input": "Explain TEE attestation in two sentences.",
    "reasoning": { "effort": "high" }
  }'

GPT-5.5 API FAQ

How much does the GPT-5.5 API cost?

6.25 per 1M input tokens and

37.50 per 1M output tokens, with cached input at $0.63 per 1M. Prices are in USD and can be paid in DIEM at parity.

What is the GPT-5.5 model ID?

Use openai-gpt-55 as the model parameter.

Is the GPT-5.5 API private?

GPT-5.5 is anonymized: Venice forwards requests to the provider without your identity, but the provider may retain prompt data, so use a private model for sensitive work.

What is the context window of GPT-5.5?

1M tokens of context, with up to 128K output tokens per response.

What does GPT-5.5 support?

GPT-5.5 supports function calling, structured outputs, reasoning, image input, web search and prompt caching. Reasoning effort is adjustable with reasoning_effort: none, low, medium, high and xhigh (default high).

Which endpoint does the GPT-5.5 API use?

Call POST /responses. /chat/completions is also supported. OpenAI reasoning models are designed around the Responses API: reasoning, tool calls and messages come back as typed output items. Venice’s /responses endpoint is in alpha.

Related models

GPT-5.4 API: $3.13 input /$ 18.80 output per 1M tokens
GPT-5.2 API: $2.19 input /$ 17.50 output per 1M tokens
Claude Opus 4.7 API: $6.00 input /$ 30.00 output per 1M tokens
Claude Opus 4.8 API: $6.00 input /$ 30.00 output per 1M tokens
Claude Opus 4.6 API: $6.00 input /$ 30.00 output per 1M tokens
Claude Opus 5 API: $6.00 input /$ 30.00 output per 1M tokens

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